Fan stator

ABSTRACT

According to some embodiments, an apparatus includes a housing, a hub, and a plurality of airfoils, each of the plurality of airfoils having a leading edge, a trailing edge, a first end, and a second end, wherein the first end of each of the plurality of airfoils is fixedly coupled to the hub and wherein the second end of each of the plurality of airfoils is fixedly coupled to the housing.

BACKGROUND

Electronic components may generate heat in order to dissipate receivedpower. The heat may damage or otherwise impair the functionality of suchcomponents. Various cooling systems have been employed to coolpower-dissipating components, which may include processors, chipsets,voltage regulator components, and other components. Some cooling systemsutilize a fan to evacuate heated air from a chassis including thepower-dissipating components. Other cooling systems generate airflowusing a fan and direct the airflow toward the power-dissipatingcomponents to provide cooling thereof

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative cutaway side view of a system according tosome embodiments.

FIG. 2 is a perspective front (inlet) exploded view of a systemaccording to some embodiments.

FIG. 3 is a perspective front (inlet) view of a system according to someembodiments.

FIG. 4 is a perspective rear (outlet) view of a system according to someembodiments.

FIG. 5 is a graph illustrating improvement in a system operating pointaccording to some embodiments.

FIG. 6 is a diagram illustrating air velocity vector conversionaccording to some embodiments.

FIG. 7 is a perspective front (inlet) view of a thermal module accordingto some embodiments.

FIG. 8 is a perspective view of a system according to some embodiments.

DETAILED DESCRIPTION

FIGS. 1 through 4 show various views of a cooling system. In particular,FIG. 1 is a representative cutaway side view, FIG. 2 is an explodedperspective view, FIG. 3 is a front (inlet) perspective view, and FIG. 4is a rear (outlet) perspective view of system 1 according to someembodiments. System 1 may comprise a system to cool devices by directingair thereto. System 1 may be used in conjunction with any suitableapplication, including but not limited to cooling electronic componentshoused in a chassis.

System 1 includes housing 10 and hub 20. A plurality of stator vanes 30are coupled to housing 10 and hub 20. According to some embodiments,each of stator vanes 30 is an airfoil comprising a leading edge, atrailing edge, a first end and a second end. The first end of eachairfoil is fixedly coupled to hub 20 and the second end is fixedlycoupled to housing 10.

Housing 10, hub 20 and vanes 30 may be composed of any materialssuitable for their intended use, including but not limited to plastics,resins, polymers, and metals. Physical dimensions of housing 10, hub 20and vanes 30 may also vary according to intended uses and/orspecifications with which system 1 is intended to comply. Housing 10,hub 20 and vanes 30 comprise a single integral unit according to someembodiments. Such a unit may be manufactured using injection moldingtechniques.

Fan 40 is coupled to hub 20 according to some embodiments. Motor 60 maybe disposed within fan 40 and supported by hub 20 as shown. Motor 60rotates blades 50 of fan 40 to deliver air to the leading edges of vanes30. As shown in FIG. 1, input air 70 at pressure P₀ is received andaccelerated due to the rotation of blades 50. The accelerated airexhibits static pressure P₁ includes a tangential velocity vector, anaxial velocity vector, and a radial velocity vector that depend at leastupon the design of fan 40, the speed of rotation and the location atwhich the accelerated air exits fan blades 50.

Vanes 30 receive the accelerated air. According to some embodiments,vanes 30 increase the static pressure of the air from P₁ to P₂ for agiven axial velocity from leading edges of vanes 30 to trailing edges ofvanes 30. The air exiting the trailing edges of vanes 30 is depicted inFIG. 1 as air 80.

For a particular fan speed, the flow and/or pressure of air 80 may begreater than would be provided by fan 40 in the absence of vanes 30.FIG. 5 depicts, for a given enclosure, operating point 0 ₁ of a systemconsisting only of fan 40 and operating point 0 ₂ of system 1. As shown,operating point 0 ₂ is associated with a greater flow and a greaterstatic pressure than operating point 0 ₁. System 1 may thereby cooldownstream components more effectively than fan 40 alone.

The leading edges of vanes 30 receive the accelerated air from fan 40.In some embodiments, the leading edge of at least one of vanes 30defines a first curve and the trailing edge of the blade defines asecond curve. Examples of the first curve and the second curve arecircumscribed by dotted line 31 of FIG. 2 and dotted line 32 of FIG. 4,respectively. The curves may reduce a radial velocity vector andincrease an inlet-to-outlet static pressure of the received air.According to some embodiments, the first curve of at least one of vanes30 is disposed perpendicular at a given radius to the trailing edge ofat least one of fan blades 50 at the given radius. This latterarrangement may reduce a total area of interaction between the vanes andthe blades at any given point in time, thereby creating less acousticnoise than alternative arrangements.

As mentioned above, vanes 30 may comprise airfoils according to someembodiments. If the accelerated air from fan 40 encounters the leadingedge of a vane 30 at an appropriate angle of attack, the airfoil shapemay produce lift that assists in converting at least some of thetangential velocity of the received air to pressure. In someembodiments, the blades comply with National Advisory Committee forAeronautics (NACA) Four-Digit Series airfoil geometries 93xx, 94xx,83xx, or 84xx. Examples of such geometries include airfoil geometries9304, 9404, 8304, or 8404. According to these embodiments, the vanes aredefined by a maximum camber of 8% or more of a length of the vanes.

FIG. 6 illustrates the transformation of the received air velocityvectors due at least in part to the above-described curvature andairfoil shape of vanes 30. Blade 50 of fan 40 is shown in cross-section.Blade 50 receives air 70 at pressure P₀ and rotates to generate air at agreater pressure P₁. The generated air is represented by vector diagram90. As shown, the velocity vector V_(total0) of the air includes anaxial component V_(axial0), a tangential (or “swirl”) componentV_(tangential0), and a radial component V_(radial0) perpendicular to thepage.

The accelerated air then encounters vane 30, also shown incross-section. Air 80 exiting from a trailing edge of vane 30 exhibitsan increase in static pressure from P₁ to P₂, while the axial velocitycomponent V_(axial1) remains substantially equal to axial componentV_(axial0). However, magnitudes of both tangential velocity componentV_(tangential1) and radial component V_(radial0) are less thanrespective components V_(tangential0) and V_(radial0) of the airreceived by the leading edge of vane 30.

The angle at which the accelerated air impinges on the leading edges ofvanes 30 may decrease with distance from hub 20. One or more of vanes 30may therefore be “twisted” such that this “vane angle” varies withradius. When such a twist is employed, the first end of one of the oneor more vanes 30 is not coplanar with the second end of the one or morevanes 30. The vane angle is measured by connecting a line between theleading edge and the trailing edge of the blade (known as the chord),where that line then intersects with a horizontal plane when the hub 15is disposed horizontally.

The vane angle may increase as a function of radius. In someembodiments, the vane angle of at least one of vanes 30 is 55 degrees athub 20 and 75 degrees at housing 10. Some embodiments may provide a vaneangle of at least one of vanes 30 that is 43 degrees at hub 20 and 73degrees at housing 10.

According to some embodiments, the number of blades 50 is N and thenumber of vanes 30 is not an integer multiple of N. Such an arrangementmay provide increased acoustic interference and thereby reduce theoperational noise of system 1 in comparison to other arrangements. In aparticular example, the number of vanes is equal to N+1. Someembodiments may also reduce acoustic noise in comparison to otherarrangements by allowing a slower rotational speed of fan 40 for a givenamount of airflow.

FIG. 7 is a perspective view of thermal module 200 using system 1according to some embodiments. Thermal module 200 also includes housing210, electronic component 300, and heat sink 310. Relevant portions ofhousing 210 are drawn as if transparent to allow viewing of electroniccomponent 300 and heat sink 310. Thermal module 200 uses air 80generated by system 1 to cool heat sink 310 according to someembodiments.

Electronic component 300 may comprise any heat-dissipating component,including but not limited to an integrated circuit (e.g.,microprocessor, chipset), and a power switching element. Heat sink 310may comprise any material (e.g. copper, aluminum) and may comprise anycurrently- or hereafter-known cooling device. As illustrated, heat sink310 includes thermally-conductive fins 315 to dissipate heat fromelectronic component 300 into the ambient air.

The above-described increased in the axial velocity component of air 80with respect to its tangential velocity component may reduce turninglosses at the edge of fins 315 as compared to other systems. Moreefficient cooling of component 300 may result. In addition, for a givenspeed of fan 40, a static pressure of air exiting module 200 may begreater than previously available.

FIG. 8 is a perspective view of system 400 according to someembodiments. System 400 may comprise a desktop computing platform.System 400 uses air 80 generated by thermal module 200 to cool multiplesystem components.

System 400 includes module 200, chassis 410, and motherboard 420.Chassis 410 is shown transparent to allow viewing of the components ofsystem 400. Module 200 of FIG. 7 may be identical to module 200 of FIG.6 except for the vertical extension of system 1 below motherboard 420.The vertical extension may allow a portion of air 80 to travel fromblades 30 to a volume between motherboard 420 and chassis 410.

Various components may be mounted to motherboard 420, including memorycontroller hub 430, I/O controller hub 440, add-in cards 450, 452 and454, memory cards 460, and I/O interfaces 470. Also included in system400 are removable media drive 480, hard disk drive 490 and power supply500. Any other system components and configurations may be used inconjunction with some embodiments.

Air 80 from thermal module may be used to cool one or more of thecomponents of system 400. In some examples, air 80 may flow overheat-dissipating components mounted on a face of graphics add-in card450, over hubs 430 and 440, and may exit through a rear panel of chassis410 (not shown). The increased axial flow with respect to tangentialflow of air 80 from system 1 may reduce losses caused by heat sink 310,thereby making more air pressure available to cool the other components.If additional air pressure is not needed, system 1 may be operated at alower fan speed and acoustic level so as to deliver a same amount ofairflow as a conventional system operating at a higher fan speed andacoustic level.

The several embodiments described herein are solely for the purpose ofillustration. Embodiments may include any currently or hereafter-knownversions of the elements described herein. Therefore, persons in the artwill recognize from this description that other embodiments may bepracticed with various modifications and alterations.

1. An apparatus comprising: a housing; a hub; and a plurality ofairfoils, each of the plurality of airfoils having a leading edge, atrailing edge, a first end, and a second end, wherein the first end ofeach of the plurality of airfoils is fixedly coupled to the hub andwherein the second end of each of the plurality of airfoils is fixedlycoupled to the housing.
 2. An apparatus according to claim 1, wherein amaximum camber of at least one of the plurality of airfoils is 8% ormore of a length of the at least one of the plurality of airfoils.
 3. Anapparatus according to claim 2, wherein each of the plurality ofairfoils complies with at least one of NACA 93xx, 94xx, 83xx, or 84xxairfoil geometries.
 4. An apparatus according to claim 1, wherein theleading edge of at least one of the plurality of airfoils defines afirst curve to reduce a tangential velocity vector and increase a staticpressure vector of air received at the leading edge.
 5. An apparatusaccording to claim 4, further comprising: a fan to deliver the air tothe leading edges of the plurality of airfoils, the fan comprising aplurality of fan blades, wherein the first curve is disposedperpendicular at a given radius to a trailing edge of at least one ofthe plurality of fan blades at the given radius.
 6. An apparatusaccording to claim 1, wherein the leading edge of at least one of theplurality of airfoils defines a first curve to reduce a radial velocityvector and increase a static pressure vector of air received at theleading edge.
 7. An apparatus according to claim 6, further comprising:a fan to deliver the air to the leading edges of the plurality ofairfoils, the fan comprising a plurality of fan blades, wherein thefirst curve is disposed substantially perpendicular at a given radius toa trailing edge of at least one of the plurality of fan blades at thegiven radius.
 8. An apparatus according to claim 1, wherein the firstend is not coplanar with the second end.
 9. An apparatus according toclaim 8, wherein the vane angle of at least one of the plurality ofairfoils is 55 degrees at the hub and 75 degrees at the housing.
 10. Anapparatus according to claim 8, wherein the vane angle of at least oneof the plurality of airfoils is 43 degrees at the hub and 73 degrees atthe housing.
 11. An apparatus according to claim 8, wherein the vaneangle increases with distance from the hub.
 12. An apparatus accordingto claim 8, wherein the leading edge of at least one of the plurality ofairfoils defines a first curve to reduce a radial velocity vector and atangential velocity vector and to increase a static pressure vector ofair received at the leading edge.
 13. An apparatus according to claim 1,further comprising: a fan to deliver the air to the leading edges of theplurality of airfoils, the fan comprising only N fan blades, wherein theapparatus comprises only M airfoils, and wherein M is not an integermultiple of N.
 14. An apparatus according to claim 13, furthercomprising: a fan motor disposed within the fan and coupled to the hub,wherein the fan is coupled to the fan motor.
 15. An apparatus accordingto claim 13, wherein M is equal to N+1.
 16. A system comprising: ahousing; a hub; a plurality of airfoils, each of the plurality ofairfoils having a leading edge, a trailing edge, a first end, and asecond end; a microprocessor; and an aluminum and copper compositeheatsink coupled to the microprocessor, the heatsink to receive air fromthe trailing edges of the plurality of airfoils, wherein the first endof each of the plurality of airfoils is fixedly coupled to the hub andwherein the second end of each of the plurality of airfoils is fixedlycoupled to the housing.
 17. A system according to claim 16, wherein amaximum camber of at least one of the plurality of airfoils is 8% ormore of a length of the at least one of the plurality of airfoils.
 18. Asystem according to claim 17, wherein each of the plurality of airfoilscomplies with at least one of NACA 93xx, 94xx, 83xx, or 84xx airfoilgeometries.
 19. A system according to claim 16, wherein the leading edgeof at least one of the plurality of airfoils defines a first curve toreduce a tangential velocity vector and increase a static pressurevector of air received at the leading edge.
 20. A system according toclaim 19, further comprising: a fan to deliver the air to the leadingedges of the plurality of airfoils, the fan comprising a plurality offan blades, wherein the first curve is disposed perpendicular at a givenradius to a trailing edge of at least one of the plurality of fan bladesat the given radius.
 21. A system according to claim 16, wherein theleading edge of at least one of the plurality of airfoils defines afirst curve to reduce a radial velocity vector and increase a staticpressure vector of air received at the leading edge.
 22. A systemaccording to claim 21, further comprising: a fan to deliver the air tothe leading edges of the plurality of airfoils, the fan comprising aplurality of fan blades, wherein the first curve is disposedsubstantially perpendicular at a given radius to a trailing edge of atleast one of the plurality of fan blades at the given radius.
 23. Asystem according to claim 16, wherein the first end is not coplanar withthe second end.
 24. A system according to claim 23, wherein the vaneangle of at least one of the plurality of airfoils is 55 degrees at thehub and 75 degrees at the housing.
 25. A system according to claim 23,wherein the vane angle of at least one of the plurality of airfoils is43 degrees at the hub and 73 degrees at the housing.
 26. A systemaccording to claim 23, wherein the vane angle increases with distancefrom the hub.
 27. A system according to claim 23, wherein the leadingedge of at least one of the plurality of airfoils defines a first curveto reduce a radial velocity vector and a tangential velocity vector andto increase a static pressure vector of air received at the leadingedge.
 28. A system according to claim 16, further comprising: a fan todeliver the air to the leading edges of the plurality of airfoils, thefan comprising only N fan blades, wherein the apparatus comprises only Mairfoils, and wherein M is not an integer multiple of N.
 29. A systemaccording to claim 28, further comprising: a fan motor disposed withinthe fan and coupled to the hub, wherein the fan is coupled to the fanmotor.
 30. A system according to claim 28, wherein M is equal to N+1.